Best way to share functionality but have different styles? - javascript

I am building a Next.js website and I am running into this issue:
I have 3 forms which work essentially the same way but they all look different. I would like to build the actual form only once but be able to somehow style it in different ways without duplicating too much code and doing things the "right way".
The solution I have come up with is to simply give the form a class and style its children via classic CSS. This works but feels "wrong" considering the rest of the project is using Styled-components. I would like to find a solution that follows the principles behind SC instead of adding global styles to the app.
This is what the code currently looks like:
// form.js
export default Form = () => {
/* ... hooks and stuff ... */
return (
<form>
/* ... */
</form>
)
}
// styled-form-1.js
import Form from './Form.js'
export default Form = () => {
return (
<Form className="styled-1" />
)
}
// globalStyles.css
.styled-1 form { /* ... */ }
.styled-1 input { /* ... */ }
.styled-1 button { /* ... */ }
.styled-2 form { /* ... */ }
.styled-2 input { /* ... */ }
.styled-2 button { /* ... */ }
As I said... This works fine but I want to do it the styled-components way. I just cannot find that solution.

You can pass function to styled-component's template literal to adapt it based on props. For example:
const Button = styled.button`
background: ${props => props.primary ? "red" : "blue"};
color: ${props => props.primary ? "blue" : "red"};
font-size: 1em;
padding: 1em;
`;
render(
<div>
<Button>Normal</Button>
<Button primary>Primary</Button>
</div>
);
By this way you can create single styled-components for your form and change it's styles based on the props. For more, check official Doc

Related

Implement live markdown rendering using slate.js

I'm writing a markdown text editor using slate.js. I'm trying to implement the following live-rendering effect (from Typora):
As you can see,
When I'm typing, the text is turning to bold automatically.
When I hit the space key, the four asterisks disappeared, only the text itself is visible.
When I focus the cursor back to the text, the asterisks shows up again (so I can modify them).
I've already implemented the first item thanks to the example of MarkdownPreview, here is the code of it (take from the slate repository):
import Prism from 'prismjs'
import React, { useCallback, useMemo } from 'react'
import { Slate, Editable, withReact } from 'slate-react'
import { Text, createEditor, Descendant } from 'slate'
import { withHistory } from 'slate-history'
import { css } from '#emotion/css'
// eslint-disable-next-line
;Prism.languages.markdown=Prism.languages.extend("markup",{}),Prism.languages.insertBefore("markdown","prolog",{blockquote:{pattern:/^>(?:[\t ]*>)*/m,alias:"punctuation"},code:[{pattern:/^(?: {4}|\t).+/m,alias:"keyword"},{pattern:/``.+?``|`[^`\n]+`/,alias:"keyword"}],title:[{pattern:/\w+.*(?:\r?\n|\r)(?:==+|--+)/,alias:"important",inside:{punctuation:/==+$|--+$/}},{pattern:/(^\s*)#+.+/m,lookbehind:!0,alias:"important",inside:{punctuation:/^#+|#+$/}}],hr:{pattern:/(^\s*)([*-])([\t ]*\2){2,}(?=\s*$)/m,lookbehind:!0,alias:"punctuation"},list:{pattern:/(^\s*)(?:[*+-]|\d+\.)(?=[\t ].)/m,lookbehind:!0,alias:"punctuation"},"url-reference":{pattern:/!?\[[^\]]+\]:[\t ]+(?:\S+|<(?:\\.|[^>\\])+>)(?:[\t ]+(?:"(?:\\.|[^"\\])*"|'(?:\\.|[^'\\])*'|\((?:\\.|[^)\\])*\)))?/,inside:{variable:{pattern:/^(!?\[)[^\]]+/,lookbehind:!0},string:/(?:"(?:\\.|[^"\\])*"|'(?:\\.|[^'\\])*'|\((?:\\.|[^)\\])*\))$/,punctuation:/^[\[\]!:]|[<>]/},alias:"url"},bold:{pattern:/(^|[^\\])(\*\*|__)(?:(?:\r?\n|\r)(?!\r?\n|\r)|.)+?\2/,lookbehind:!0,inside:{punctuation:/^\*\*|^__|\*\*$|__$/}},italic:{pattern:/(^|[^\\])([*_])(?:(?:\r?\n|\r)(?!\r?\n|\r)|.)+?\2/,lookbehind:!0,inside:{punctuation:/^[*_]|[*_]$/}},url:{pattern:/!?\[[^\]]+\](?:\([^\s)]+(?:[\t ]+"(?:\\.|[^"\\])*")?\)| ?\[[^\]\n]*\])/,inside:{variable:{pattern:/(!?\[)[^\]]+(?=\]$)/,lookbehind:!0},string:{pattern:/"(?:\\.|[^"\\])*"(?=\)$)/}}}}),Prism.languages.markdown.bold.inside.url=Prism.util.clone(Prism.languages.markdown.url),Prism.languages.markdown.italic.inside.url=Prism.util.clone(Prism.languages.markdown.url),Prism.languages.markdown.bold.inside.italic=Prism.util.clone(Prism.languages.markdown.italic),Prism.languages.markdown.italic.inside.bold=Prism.util.clone(Prism.languages.markdown.bold); // prettier-ignore
const MarkdownPreviewExample = () => {
const renderLeaf = useCallback(props => <Leaf {...props} />, [])
const editor = useMemo(() => withHistory(withReact(createEditor())), [])
const decorate = useCallback(([node, path]) => {
const ranges = []
if (!Text.isText(node)) {
return ranges
}
const getLength = token => {
if (typeof token === 'string') {
return token.length
} else if (typeof token.content === 'string') {
return token.content.length
} else {
return token.content.reduce((l, t) => l + getLength(t), 0)
}
}
const tokens = Prism.tokenize(node.text, Prism.languages.markdown)
let start = 0
for (const token of tokens) {
const length = getLength(token)
const end = start + length
if (typeof token !== 'string') {
ranges.push({
[token.type]: true,
anchor: { path, offset: start },
focus: { path, offset: end },
})
}
start = end
}
return ranges
}, [])
return (
<Slate editor={editor} value={initialValue}>
<Editable
decorate={decorate}
renderLeaf={renderLeaf}
placeholder="Write some markdown..."
/>
</Slate>
)
}
const Leaf = ({ attributes, children, leaf }) => {
return (
<span
{...attributes}
className={css`
font-weight: ${leaf.bold && 'bold'};
font-style: ${leaf.italic && 'italic'};
text-decoration: ${leaf.underlined && 'underline'};
${leaf.title &&
css`
display: inline-block;
font-weight: bold;
font-size: 20px;
margin: 20px 0 10px 0;
`}
${leaf.list &&
css`
padding-left: 10px;
font-size: 20px;
line-height: 10px;
`}
${leaf.hr &&
css`
display: block;
text-align: center;
border-bottom: 2px solid #ddd;
`}
${leaf.blockquote &&
css`
display: inline-block;
border-left: 2px solid #ddd;
padding-left: 10px;
color: #aaa;
font-style: italic;
`}
${leaf.code &&
css`
font-family: monospace;
background-color: #eee;
padding: 3px;
`}
`}
>
{children}
</span>
)
}
const initialValue: Descendant[] = [
{
type: 'paragraph',
children: [
{
text:
'Slate is flexible enough to add **decorations** that can format text based on its content. For example, this editor has **Markdown** preview decorations on it, to make it _dead_ simple to make an editor with built-in Markdown previewing.',
},
],
},
{
type: 'paragraph',
children: [{ text: '## Try it out!' }],
},
{
type: 'paragraph',
children: [{ text: 'Try it out for yourself!' }],
},
]
export default MarkdownPreviewExample
My question is, how can I implement the second and third items? I've been thinking about it for a long time, but didn't find any good way to achieve them.
The good news:
The original text is saved unharmed (somewhere in your application)
Slate.js is rendering a new element for each style. thanks to the live demonstration link you've posted it is clear that the DOM is saving the state of your markdown (which suggest that we can add manipulations on-top of slate if required)
The bad news:
Implementing an editor is a headache. Using an existing one is not always as intuitive and easy as we expected. That's why I love the Monaco editor project so much (a free editable editor that gives me the experience of VS code for free? yes please!)
What we can do?
the easy way:
Use Monaco editor in our project. From my experience - it is better in terms of coding and formatting technical texts (and maybe this is the engine behind VS code)
The not-so-easy way:
We can make a simpler implementation - a panel with the raw text and another panel for preview (by the way - this is exactly what happens when you edit markdown files in VS code anyways). That way we can always render the view to reflect our most recent changes. For starters - you can use this project to do it and add tweaks to it so suit your demands
The hard way:
Using slate.js commands (read this doc for the general concept + useful examples). This approach will let slate handle the load but requires you to deep-dive into that project as well. Note that you can register custom commands and queries to suit your need without breaking your work pipeline (read this)
The insane way:
Try to override slate by using custom events on-top of rendered elements. This can be tricky but achievable if you love to play with projects internals and inject values on the fly. Not very recommended though
My Recommendation
Create a custom command that will apply the markdown style you want (for instance: bold)
Use slate handler for tracking the space key hit and use your command
function onKeyDown(event, editor, next) {
if (event.key == 'Enter') {
// TODO: add markdown style
editor.applyMarkdownBold() // applyMarkdownBold is a made-up name for your custom command
} else {
return next()
}
}
I know - this example will apply bold style to all text but - if you combine it with a range selection you will get the style you need for the relevant area in you editor (again - docs for the rescue)
From this point - applying a specific selection via key press or adding the markdown characters by clicking it (using an event + query + command) is only a matter of time

How to pass custom data-attribute to styled component?

I have this Styled component, where I'm trying to pass DATA-attribute which is coming from props to it. (This is the solution we have on Stack Overflow)
export const InlineEditReadViewErrorContainer = styled.div.attrs(props => ({
'data-cy': props.dataCy
}))`
border: 2px solid #de350b;
border-radius: 3px;
`;
This is how I use this styled component in code
<InlineEditReadViewErrorContainer dataCy='blabla'>
{readView}
</InlineEditReadViewErrorContainer>
But this is doesn't change anything
I think that we must use correctly the attributes that are added to a component in React and more if they are needed only to style a component.
We should use as many native properties as possible but without compromising the private data that would be exposed in the HTML that the client displays in broser, therefore:
If you are going to use data-attributes:
Remember how to name these attributes:
The attribute name should not contain any uppercase letters, and must be at least one character long after the prefix "data-"
Note: I would just use the simplest possible, with booleans to give a set of properties as the first answer described, for example:
component.js
<Error data-active={true}>
{readView}
</Error>
component.styles.js
export const Error = styled.div`
&[data-active="true"] {
border: 2px solid #de350b;
border-radius: 3px;
}
`;
If you want to use custom props without them being displayed in the DOM as the second comment has described, using transient props:
For sample:
component.js
<Error $active={true}>
{readView}
</Error>
component.styles.js
export const Error = styled.div`
${({$active}) => $active ? css`
border: 2px solid #de350b;
border-radius: 3px;
`: null}
`;
The prop should already be "passed" in the sense that it will show up on the component for the purposes of using it in Cypress. If you want to use it internally you could also use transient props such as this
const Comp = styled.div`
color: ${props =>
props.$draggable || 'black'};
`;
render(
<Comp $draggable="red" draggable="true">
Drag me!
</Comp>
);
It was much easier. You can pass the data attribute directly where you use the styled component and everything will be fine.
<InlineEditReadViewErrorContainer data-cy='dateInput'>
{textValue}
</InlineEditReadViewErrorContainer>
Maybe it's related to your bundler, since you should be able to pass a data attribute to a styled-component directly. However, if you're extending an existing component, be aware that you need to pass it through props. Those two situations will attach the data attribute to the final HTML:
function Text(props) {
return (
<p data-foo={props['data-foo']} className={props.className}>
{props.children}
</p>
);
}
const StyledText = styled(Text)`
color: blueviolet;
`;
const StyledHeading = styled.h1`
color: gray;
`;
export default function App() {
return (
<div>
<StyledHeading data-bar="foo">Hello StackBlitz!</StyledHeading>
<StyledText data-foo="bar">
Start editing to see some magic happen :)
</StyledText>
</div>
);
}

Next.js - Cant apply dynamic class names when using CSS Modules

hoping someone here can help me solve this.
Am trying to build a website through NextJs. One of my pages has some paragraphs and buttons which are styled differently based on states and events. I can get the styling to work as intended when using pure React, and also when using a Global Stylesheet with NextJs; but when I use CSS Modules I cant get it to function as intended.
(Note: I can also get it to work by using a simple ternary like
<h1 className={submitted ? styles.showresult : styles.hideresult}>Correct? {correct}</h1>;
but I have some other scenarios where I need to rely on an multiple ifs and create multiple classes, each with their own styling, so I cant make a simple ternary my final solution.
E.g. this is the file pagex.js
import React from 'react';
import ReactDOM from 'react-dom';
const Pagex = () => {
const [submitted, setSubmitted] = React.useState(false); // whether the submit button was pressed
function calculateScore() {
let correct = 0
let incorrect = 0
//......some scoring logic.....
setSubmitted(true)
}
// function to create a display class based on whether the submit button has been pressed
function displayResult(){
if (submitted === true) {
return "showtheresult"
} else {
return "hidetheresult"
}
}
return (
<section className="results">
<h1 className={displayResult()}>Correct? {correct}</h1>
<h1 className={displayResult()}>Incorrect? {incorrect}</h1>
<button className={displayResult()} onClick={handleMovClick}>An instruction</button>
</section>
</div>
);
};
export default Pagex;
the globals.css file contains
h1.hidetheresult, h3.hidetheresult {
visibility: hidden;
}
h1.showtheresult, h3.showtheresult {
visibility: visible;
}
button.hidetheresult {
border-color: pink;
}
button.showtheresult {
border-color: aqua;
}
Changes when using CSS modules
Add a CSS file in the correct folder with the correct name
(../styles/Pagex.module.css) which contains the same styling shown
above
Additional import in pagex.js import styles from '../styles/Pagex.module.css'
Change reference in the function
within pagex.js
function displayResult(){
if (submitted === true) {
return {styles.showtheresult}
} else {
return {styles.hidetheresult}
}
}
When i do this the '.' in {styles.showtheresult} and {styles.hidetheresult} gets highlighted as an error by vscode with this detail: ',' expected. ts(1005).
Saving the js with a dev server running shows a similar message after trying to compile: Syntax error: Unexpected token, expected "," and the browser shows the same message along with "Failed to compile"
Also tried just passing styles.showtheresult / styles.hidetheresult by removing the curly braces from the displayResult() function. That compiles but nothing happens on the compiled webpage, i.e the class doesnt get updated when the button is pressed and so the styling cant be applied.
Also Tried passing as ${styles.showresult} and ${styles.hideresult} (with `)in the return statement. That also compiles but the page itself gives me an "Unhandled Runtime Error ReferenceError: styles is not defined" message and I cant load the page.
Would highly appreciated if someone could help correct my syntax in the function itself or elsewhere in the code.
Because you asked nicely ;) (just kiddin')
So Next.js is an opinionated framework and uses CSS Modules to enforce component scoped styling.
Basically you define your stylesheet with a name.module.css filename and add regular CSS in it.
.hidetheresult {
visibility: hidden;
}
.showtheresult{
visibility: visible;
}
.btn-hidetheresult {
border-color: pink;
}
.btn-showtheresult {
border-color: aqua;
}
Now to use this, import it like any JS module,
import styles from './styles.module.css'
console.log(styles);
// styles => {
// hidetheresult: 'contact_hidetheresult__3LvIF',
// showtheresult: 'contact_showtheresult__N5XLE',
// 'btn-hidetheresult': 'contact_btn-hidetheresult__3CQHv',
// 'btn-showtheresult': 'contact_btn-showtheresult__1rM1E'
// }
as you can see, the styles are converted to objects and now you can use them
like styles.hidetheresult or styles['btn-hidetheresult'].
Notice the absence of element selector in the stylesheet. That's because CSS Modules rewrite class names, but they don't touch tag names. And in Next.js that is
the default behaviour. i.e it does not allow element tag selectors.
File extensions with *.module.(css | scss | sass) are css modules and they can only target elements using classnames or ids and not using tag names. Although this is possible in other frameworks like create-react-app, it is not possible in next-js.
But you can override it in the next.config.js file. (Beyond the scope of this answer)
There is an article which explains how to override it. - disclaimer: I am the author
Now coming to your use-case, you can do contitional styling like so: (assuming the styles are as per the sample given in the answer)
import React from "react";
import styles from "./styles.module.css";
const PageX = () => {
const [submitted, setSubmitted] = React.useState(false);
const getStyle = () => {
if (submitted) return styles.showtheresult;
else return styles.hidetheresult;
};
const getButtonStyle = () => {
if (submitted) return styles["btn-showtheresult"];
else return styles["btn-hidetheresult"];
};
return (
<div>
<section className="results">
<h1 className={getStyle()}>Correct?</h1>
<h1 className={getStyle()}>Incorrect?</h1>
<button className={getButtonStyle()} onClick={handleMovClick}>
An instruction
</button>
</section>
</div>
);
};
As you add more conditions, the methods do tend to get more complex. This is where the classnames
module comes handy.
import styles from "./styles.module.css";
import clsx from "classnames";
const PageX = () => {
const [submitted, setSubmitted] = React.useState(false);
const headerStyle = clsx({
[styles.showtheresult]: submitted,
[styles.hidetheresult]: !submitted,
});
const btnStyle = clsx({
[styles["btn-showtheresult"]]: submitted,
[styles["btn-hidetheresult"]]: !submitted,
});
return (
<div>
<section className="results">
<h1 className={headerStyle}>Correct?</h1>
<h1 className={headerStyle}>Incorrect?</h1>
<button className={btnStyle} onClick={handleMovClick}>
An instruction
</button>
</section>
</div>
);
};
Here's a CodeSandbox for you to play with:

React too many re renders infinite loop

I'm not sure why i'm getting this error, i'm just trying to make a button that inverts colors on hover, if you have a solution or a better way to do this please let me know
import React, {useState} from 'react'
function Login() {
const [bttnColor, setBttnColor] = useState('white')
const [textColor, setTextColor] = useState('black')
function colorChange1(){
setBttnColor('black')
setTextColor('white')
}
function colorChange2(){
setBttnColor('white')
setTextColor('black')
}
return (
<div className="Login" style={{display:'flex', flexDirection:'column', justifyContent:'center', alignItems:'center'}}>
<h1 style={{display:'flex', marginTop:'400px', marginBottom:'40px'}}>Login</h1>
<input style={{height:'30px', width:'140px', marginBottom:'10px'}} placeholder='Username'/>
<input style={{height:'30px', width:'140px'}} type='password'placeholder='Password'/>
<button style={{height:'30px', width:'140px', marginTop:'10px', background:bttnColor, color:textColor}} onMouseEnter={colorChange1()} onMouseLeave={colorChange2()}>Login</button>:
</div>
)
}
export default Login
When declaring a property, the result of what's inside of the {} is sent to the Component.
This will send the result of colorChange1() to the component, not the function itself
onMouseEnter={colorChange1()}
This is unwanted behavior in your use case, but remember that this is a property just like any other, like style or className.
You need to pass it a function reference instead of the result of the function. You can do that in two different ways:
onMouseEnter={colorChange1}
onMouseEnter={(event) => colorChange1(event, otherVariables...)}
The first way is a function reference to the existing function. Use this when you don't need to pass any other information to the function
The second way is to wrap the function call with a lambda. This will allow you to take variables from your current scope and pass them into the method when it's run.
EDIT:
On second thought, doing this at all is making it far more complicated than it needs to be. This can be done in a few lines of CSS.
Let's remove those color change methods and the onMouseEnter and onMouseLeave calls, and give the button a className so we can refer to it in CSS.
<button className="login-button">Login</button>:
Then let's create the following css file, named Login.css in the same folder as Login.js:
.login-button {
height: 30px;
width: 140px;
marginTop: 10px;
background:white;
color:black;
}
.login-button:hover {
background: black;
color: white;
}
Finally, let's import the css file:
import "./Login.css";

How can i dynamically assign the props as variables to colors from my own color pallet in scss/css with react?

I am calling a component "MyRadioButton" with following props:
<MyRadioButton
label="Radio Group"
theme="custom-red" //this line
error="Field is required "
radioBtns={options}
id="radioBtns"
name="radioBtns"
getValue={this.getValue}
/>
I have created a react component "MyRadioButton" that will accept color name(theme) as props.
export const MyRadioButton = props => {
const {theme} = props;
return (
<div className="my-radio-buttons"> // need to use theme here
<input
onChange={onChange}
type="radio"
/>
</div>
)}
Based on this prop i want to assign the variable in my components scss file, which will take the color code from my custom defined color pallet.
my-radio-button.scss
/* custom color pallet */
$custom-orange: #F060D6;
$custom-red: #BB532E;
$custom-blue: #4C9FEB;
.my-radio-buttons {
.input{
border: 2px solid $custom-red; // i want to assign the color variable based on input prop value to this property
}
}
I have already tried setting variable at css root with javascript and accessing it with variable function var(), it works fine.
But because of some limitations i dont want to use that approach.
also because the color pallet list is huge, i dont want to use separate classes for all of them.
I am looking for some other solution or different approach.
So you can use a combination of custom css variables and your passed theme property. In you css, you would define the basecolor of the border for example:
.my-radio-buttons {
--theme-color: red;
input {
border: 2px solid var(--theme-color);
}
}
This can be updated by your components via componentDidMount or useEffect with the passed theme:
const MyRadioButton = props => {
const { theme } = props;
React.useEffect(() => {
const input = document.querySelector(".my-radio-buttons input");
input.style.setProperty("--theme-color", props.theme);
}, []);
return (
<div className="my-radio-buttons">
<input />
</div>
);
};
Depending on your code style, you can replace the querySelector with a ref.

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